One mole of a gas absorbs $200 \ J$ of heat at constant volume. Its temperature increases from $298 \ K$ to $308 \ K$. The change in its internal energy is ....... Joules.

Express the change in internal energy of a system when
$(i)$ No heat is absorbed by the system from the surroundings,but work $(w)$ is done on the system. What type of wall does the system have?
$(ii)$ No work is done on the system,but $q$ amount of heat is taken out from the system and given to the surroundings. What type of wall does the system have?
$(iii)$ $w$ amount of work is done by the system and $q$ amount of heat is supplied to the system. What type of system would it be?

$q$ and $w$ are both ....... functions and $q + w$ is a ....... function.

If $1.5 \ L$ of an ideal gas at a pressure of $20 \ atm$ expands isothermally and reversibly to a final volume of $15 \ L$,the work done by the gas in $L \ atm$ is

In a cylinder,$1.0 \, \text{kcal}$ of heat is added to $1.2 \, \text{L}$ of $O_2$ gas at a constant pressure of $1 \, \text{atm}$. The volume changes to $1.5 \, \text{L}$. Calculate the change in internal energy $(\Delta U)$ for this process. (in $, \text{kcal}$)

Which of the following statements is correct?